The present invention relates generally to gas generating systems, and more particularly, to gas generating systems capable of producing a product gas, such as oxygen or nitrogen, at two different pressures.
U.S. Pat. No. 5,858,062, incorporated by reference in its entirety into this specification and assigned to the instant assignee discloses an apparatus for providing oxygen-enriched air at a first pressure and at a second pressure with the second pressure being greater than the first pressure. As disclosed in the ""062 patent the apparatus includes a pressure swing adsorption system and a pressure intensifier. The pressure swing adsorption system is adapted to provide oxygen-enriched air to a first outlet at the first pressure and to provide oxygen-enriched air to a pressure intensifier at the first pressure. The pressure intensifier pressurizes the oxygen-enriched air and provides the oxygen-enriched air to a second outlet at the second pressure. Disadvantageously, the system disclosed in the ""062 patent charges or fills a high pressure vessel at constant rate whether or not there is flow on the low pressure output port. This requires a long period of time to charge a vessel (i.e., 8 hours to charge 240 liters at constant rate of 0.5 liters per minute (1 pm). Thus, a need exists in the art for a system which can simultaneously provide product gas to a high pressure outlet and a low pressure outlet where the high pressure charging rate can be varied depending upon the flow required from the low pressure outlet.
It is, therefore, an object of the present invention to provide a gas generating system capable of charging a gas cylinder faster than prior art systems.
These and other objects of the present invention are achieved by an apparatus for supplying gas at a first pressure and at a second pressure. The apparatus includes a gas generating system having a gas generating system outlet. A flow switch is in communication with the gas generating system outlet and has an outlet thereof forming a gas outlet at the first pressure. A pressure regulator is in communication with the gas generating system outlet for regulating gas flowing to the gas outlet at the first pressure. A solenoid valve is electrically controlled by the flow switch and is in communication with the gas generating system outlet and has a solenoid valve outlet. A pressure intensifier is in communication with the solenoid valve for raising the pressure of the gas generated by the gas generating system for output to an outlet at a second pressure.
The foregoing and other objects of the present invention are achieved by a method of charging a high pressure reservoir with product gas at a variable rate. The method provides oxygen enriched gas to a low pressure outlet and to a pressure intensifier. A flow rate of oxygen enriched gas is detected flowing to the low pressure outlet. A flow rate to the pressure intensifier is controlled based on the detected flow to the low pressure outlet.
The foregoing and other objects of the present invention are achieved by an apparatus for supplying gas at a first pressure and at a second pressure. The apparatus includes a gas generating system having a gas generating system outlet in communication with a low pressure outlet and a high pressure outlet. A flow switch and detector is in communication with a gas generating system outlet and detects a gas flow rate through to a low pressure. A controller controls gas flow to high pressure based on a signal supplied by a flow switch. A pressure intensifier is in communication with a high pressure outlet for raising the pressure of the gas generated by a gas generating system for output to a high pressure reservoir.
The gas generating system with multi-rate charging feature according to the present invention can easily double and up to quadruple the charging rate as compared to prior art charging systems when there is no flow at the low pressure outlet. This reduces the charging time in half.
Still other objects and advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein the preferred embodiments of the invention are shown and described, simply by way of illustration of the best mode contemplated of carrying out the invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawings and description thereof are to be regarded as illustrative in nature, and not as restrictive.